I would add, to Keith's list, for completeness:
--Adjustable CG (longitudinal axis)
--Adjustable gear height and stance. One might also include tracking. You might want to make changes based on surface (pavement vs. grass), for example
--If you didn't include the Rabe rudder, you might include instead a fixed offset, ground adjustable rudder.
--For those that mess with it, you might want to change engine offset, or if your building alignment isn't good, a vertical thrustline tweak
Some of these you get right once, and practically never change again, and others are endlessly fiddled with. I can recall one flyer that used lead shot for wingtip weight. Between every flight he would add or take out at least one pellet. I think if conditions changed, he changed the weight. If the ice cream truck drove by he changed the weight,,,,
Of course, we always adjust power level and propeller pitch as well. Which is a whole 'nuther discussion.
To some extent, if the kit is very well engineered, and it is built nearly perfectly, and if the flyer is not too picky, most of these adjustments are less critical. On old designs things were somewhat adjustable but often involved a knife and glue. Most flyers wouldn't settle for that nowadays....